Air fresheners of several types are known in the market. Worth mention are those that do not require the use of electricity and consist of a vessel containing the scented liquid or perfume and allow the exit of a wick that is partially in contact with the scented liquid, from where the scent is diffused outwards, and other air fresheners that require electricity to drive an inner fan that helps distribute the scent of the scented liquid in the premises in which it is located.
The invention disclosed herein belongs to the group of non-electrical air fresheners.
Worth mention within the field including this type of air fresheners is the invention patent ES1 051 172, which relates to an air freshener device consisting of a perfume-containing vessel that in position of non-use closes its mouth with a cap that is completed with other means to transfer the perfume in the vessel to the surroundings.
More specifically, the air freshener device incorporates associated to its threaded cap a wick support that hangs internally in the vessel and in its vertical displacement rubs against a guide stopper inserted internally in the mouth of the vessel. The amount of perfume diffused is regulated by changing the portion of the wick that projects above the vessel by pulling the cap manually upwards, stabilising the various possible positions of the wick by its rubbing with the guide stopper. This system for adjusting and stabilising the position of the wick based on mutual continuous friction leads to an early wear of these surfaces that makes the air freshener useless after a short time.
On the other hand, this patent considers the incorporation of hooks on the back end of the wick support, so that when the wick support reaches its position of maximum extraction these act as stops in the rear edge of the stopper to prevent its exit. The repeated contact of the hooks and the stopper causes a deformation of the wick support that results in a reduced positional stability of the wick.
Invention patent ES 2 160 033 belonging to the applicant of the present invention discloses a stopper for vessels containing evaporable liquids having an annular body with a neck for coupling and retention on the opening of a vessel provided with an axial passage for positioning the wick that incorporates means for retaining and immobilising the wick that together prevent the vessel from being refilled.
In the latter invention patent, as well as in the one cited before, the possibility is not considered of a stable system that allows changing the exposed surface of the wick and thus regulating the evaporation, which is the object of the invention described hereunder.